Abstract [en]

Seven decades of mining activity on the Khibiny apatite-nepheline ore deposits and current large excavation volumes have resulted in elevated concentrations of total dissolved solids and metals in various waters near the mines. To assess the major sources of pollution inputs and fate of pollutants in watercourses draining the mine workings, snow cover, surface waters, and deposited and suspended sediments were sampled and analyzed. Water chemistry data showed that discharges of the mine wastewater are the main contributor to solute and metal loads in the streams. Atmospheric transport of metals and their accumulation in the snowpack account for a sharp increase in metal concentrations in stream waters during spring snowmelt. Data on bed and suspended sediments indicated that the streams have a low capacity of immobilization of metals. The dominant mechanism responsible for decrease in solutes in watercourses is dilution. The results demonstrated the necessity for remediation actions to address pollutant loads due to wastewater discharges